Electrode assembly of electronic valves



May 30; 1944. B. ERBER ELECTRODE ASSEMBLY OF ELECTRONIC VALVES Filed July 22; 1942 r e m m n @4 1 J m M m2 M 4, i I iillizill 3/ 6 V W 7 2 WV VIIIHIIHIIHHHHHI 7 F 0 (LJ T7 1.5? .4 g A l|||||||||||| F EH 7 2 I a 2 1%? M F110, F fi m.- fir m u w w W. H. 0 U I? m U 0 B m I May 30, 1944, B. ERB ER ELECTRODE ASSEMBLY OE ELECTRONIC VALVES Filed July 22, 1942 2 Sheets-Sheet 2 Patented May 30, 1944 Bernhard Erber, St. Johns Wood, London,"

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Application July 22, 1942, Serial No. 451,979 In Great Britain January 26, 1942 8 Claims. -(Cl. 250=27.5)

This invention relates to improvements in electronic valves, more especially as regard the electrode assembly.

It aims at simplifying manufacture and facil itating mass production, more particularly of such valves as contain more than one grid, although it is applicable to certain types of valves which do not contain a grid.

Multiplegrid valves more particularly present difficulties in so far as the assembling-.01 the mounts is concerned and it is necessary for this purpose to thread parts directly associated withthe grids into a number of holes, for example live or more holes in micas. These micas are provided for keeping the whole electrode mount in fixed position and for ensuring the necessary insulation between the difierent parts.- It is the usual practice to employ suchmicas, e. g. discs,

at the top and bottom of a mount. The assembling of the grids in these micas becomes the more difllcult, as, very often, thesegrids have to be very close to each other and have to be slipped one over the other in mounting. Another difflculty is that, after having inserted all the parts directly associated with the grids into one mica,

sembled in correct relationship with respect to each other and to the valve.

Preferably the grid support is constructed to permit the several grid parts, at one side of the space to be occupied by the cathode, to be first placed in position, then the cathode to be placed in position, and, after, .this, the remaining grid parts to be assembled onto the first placed grid parts, from the opposite side of the cathode con- .taining space. i

According to one construction, the grid support comprises, a pair of mica or other suitable insulating sheets or strips having open ended slots and fixed in spaced relationship one to the other on a provisional mounting device and kept in this position during the assembly procesathe the other mica has to be mounted on those same parts without deforming or altering the distance between the grids. I

This work requires longtraining, careful attention and is a strain on the operatives eyes. is

The present invention includes as its objects the overcoming of the aforesaid difliculties, the

provision of anfimproved mechanicalmounting and also aims at ensuring that the grids can be as;-

semb'led without deformation by mechanical strain; it has for a further object to enable the operator, to perform this work accurately without having had a previous longtraining.

An electronic valve according to the present.

invention comprises a grid structure of a kind which may be termed a composite grid Here-. inafter and in the claims the terms composite electrode. composite grid," and "composite anode are to be understood as defining respectively a valve electrode, a grid, a grid structure, or an anode composed of a number oi substantially equai separate preshaped discontinuous parts following each other without intervening space, so as to supplement each othenin forming one electrode extending in cross section along a closed curve, such as, e. g., a closed circle. Cooperating with the parts of such a composite grid is a grid support including elements adapted to also form a. jig which during the manufacture of the valve ensures that said grid parts are asaforementionedgrid parts having projections at their ends which engage in the slots to locate said grid parts in their correctly assembled positions, means being provided for retaining the projections in the slots.

The grid parts may be made by initially forming the grid in one piece and welding it to pairs of juxtaposed supporting rods then separating it, between said juxtaposed rods, into its respective parts forming complementalsemicylindrical half parts.

This invention of example with reference to the accompanying drawings in which: 1

Fig. 1 is an exploded view; of part of a pentode valve assembly according to one form of the pres= ent invention. i g c Fig. 2 is a plan of a certain detail namely, a part of the jig like grid support. V

Fig. 3 is a plan of the complete electrode assembly.

Fig. 4 is a front elevation sembly.

- Fig. 5 is a plan of an alternative form similar to i Fig. 201 means for retaining the projectionsin the slots of the grid supports.

Fig. 6 is a perspective view illustrating a slighimicas for the ly modified method of preparing the electrode assembly.

Fig. 7 -is a plan showing the invention applied to a diode valve.

Fig. 8 is a plan of modification of. the part shown in Fig. 5.

Fig. 9 is a view of an alternative arrangement v to that shown in Fig. 6. v

Fig. 10 is a plan view showing the invention applied to a valve containing two cathodes and two anodes.

ornca other electrodes of the will now be described by way of the electrode as-- in the slots of a provisional support 3 indicated,

in dotted lines.

The edge of each of the micas is provided with pairs of slots, 4, I, 5, 5, and 6, 6.

l, 8 and 9 indicate respectively the semi-"cylindrical halt portions of the composite suppressor,

screen and control gridsof a pentode valve which are provided at their ends with projections It. By the term semi-circular Iwant to embrace a half grid whose wires extend in the form of the half or a circle proper, of the half of an oval, or of the half of any other closed curve.

In the assembly of the valve one half of the composite suppressor grid I is inserted between the micas I, 2, so that its projections Ill enter the twopairs of slots 4, 4, the corresponding half grid portions 8 and 9 then being successively inserted between the same micas so that their projections III respectively enter the slots 5, and 6, 6. I

Provided at a point midway long the. edge of each of the micas I, 2, is a slot II in which is next placed the cathode i2, after which the other half grid portions 9, 8 and lyare successively placed in position with the respective projections ID in the pairs of slots 6, 6, 5, 5, and 4, 4.

After the assembling of the grid parts and cathode has been effected as just described a. mica strip such as I3, Fig. 2, is placed over each of the micas I, 2, to hold the projections ID in the slots.

Each of the mica strips I3, which near eachof its ends is provided with a perforation I4 which coincides with a perforation I5 in the respective micas l and 2 is secured to its respective adjacent strip by a hollow rivet I6 (Figs. 3 and 4) The projections I 0 of the respective pairs of grid parts are then welded together at their outer ends, and the anode carrying rods I! are passed through the hollow-rivets l6 and welded therein, after which the assemblyis removed from the support 3 and the anode I8 is applied to the rods IT as shown in Figs. 3 and 4.

- Instead of employing the strip I3 for retaining the projections III in the aforesaid slots a strip such as I3a, Fig. 5, having an unserrated inner edge may be employed for the same purpose. Altematively, a strip suchas I 31;, Fig. 8, may be used instead of the strip I3a, which strip has a cathode engaging slot I30.

Preferably the strip I3a or I3b is riveted to one end of the'micas I and 2, as shown in Fig. 6 or 9, as the case may be prior to the assembly of the electrodes, as this enables said strips I311 to be merely hinged over in their final or slot closing positions after the electrodes have been assembled in the respective slots.

Fig. 7 is a plan showing the invention applied to a diode valve in which it will be seen that the anode is formed in two parts I9, I9, having projections 20 which engage in the slots 2|, 2| of a pair of micas such as 22, the said projections 20 being retained in the slots 2| by a strip 23 similar to the strip I 30., or I3b, as the case may, be, the said anode parts being insulated from each other by mica fillets 24 and being individuallv connected by a leading-in wire (not shown) to pins or the like (also not shown) upon the outside of the valve which may then be connected together to constitute the anode parts of a single anode 0; may be left disconnected when required, for example when the valve is to function as a double diode valve or as a full-wave rectifier. The projections 20 would not of course in this case be welded to each other as was the case with the projections Ill.

Obviously the anode and/or one or more of the grids of a valve according to the present invention may have its or their parts, as the case may be,

insulated from each other in the manner just described and the parts so insulated connected to separate leading in wires so that some of the parts of the electrode or electrodes so arranged may be isolated where required and connected externally with different circuits for example. i

I have found that discharge tubes (radio) valves with more than one cathode (indirectly or directly heated full wave rectiflers) when constructed according to the present invention, are much easier to assemble.

An example of a construction such as that just referred to is'shown in plan in Fig. 10 in which the overlapping micas 25, 26 hold in position the cathodes 21, 28 and the anodes 29, 30, which anodes are each formed in two parts and supported on rods 29a, 30a, the projecting end portionsof which rods are held in slots 3I in a manner similar to the rods of the grids hereintofore described, the cathodes beingin like mannerretained in slots 32.

Should the cathode, being closed on one side and having on the top of the closed parta piece of rod, then this side of the cathode' is to be.

parts and a grid support including a pair of sheets of insulating material fixed in spaced relationship one to the other and having open ended slots which receive the grid projections and locate the grid parts in their correctly assembled positions, together within means which retain the projections within the slots, comprising strips of insulating" material which engage said projections and in effect close said slots, and means which fix the grid projections to there-- spective strips comprising the grid support, said fixing means also holding the anode support.

2. An electronic valve having a composite grid formed of substantially equal separate pre-.

shaded discontinuous parts, and a jig like support for said grid, holding said parts in a united assembly.

3. An electronic valve electrode assembly having a composite grid formed of substantially equal separate pre-s'haped discontinuous parts. and a jig like support for said grid, holding said parts in a united assembly.

a 4. The method of making grid parts to be'as-= sembled in an electronic valve to form a. com

posite grid, comprising the steps of initially forming a grid in one piece and welding it to pairs of juxtaposed support rods, then separating it between said juxtaposed rods into substantially equal discontinuous parts.

-' 5. An electronic valve comprising at least one composite electrode formed of two pre-shaped substantially semi-cylindrical parts, projections on said electrode parts extending longitudinally beyond these electrode parts, and an electrode support forming a jig which holds said electrode parts in a united assembly, said support comprising two pairs oi. sheets of insulating material spaced from each other, each pair extending substantially in a plane perpendicular to 'thelongitudinal axis of said composite electrode and consisting of a sheet having open-ended slots for the reception of said projections and a retaining sheet for engaging said projections and closing said slots. 1

6. An electronic valve having at least one composite electrode formed of a number {of preshaped substantially semi-cylindrical parts, projections on said electrode parts extending longitudinally beyond these electrode parts, and an electrode support forming a jig which holds said electrode parts in a united assembly, said support comprising two pairs of sheets of insulating material spaced from each other, each pair extending substantially in a plane perpendicular to the longitudinal axis of said composite electrode and consisting of a sheet having open-ended slots for the reception of said projections and a retaining sheet for engaging said projections and closing said slots, and each of said electrode parts having attached thereto a separate leading in conductor.

7. Anelectronic valve having a composite anode formed of a number of substantially equal separate pre-shaped discontinuousparts, projections on said anode parts extending longitudinally be- 5 yond these anode parts, and an electrode support forming a jig which holds said anode parts in a united assembly, said support comprising two pairs of sheets of insulating material spaced from each other, each pair extending substantially in a plane perpendicular to the longitudinal axis of said composite anode and consisting of a sheet having open-ended slots for the reception of said projections and a retaining sheet for engaging said projections and closing said slots. 15 8. An electrode assembly for an electronic valve shaving a composite anode formed of a number of substantially equal separate pre-shaped discontinuous parts, projections on said anode parts extending longitudinally beyond these anode 20 parts, and an electrode support forming a. jig

which holds said anode parts in a united assembly, said support comprising two pairs of 30 BERNHARD ERBER. 

